Process of recovering ammonia and heating air in the manufacture of producer-gas.



PATENTED APR. 28 w. GROSSLEY & T. RIGBY PROCESS OF REGOVERINGAMMONIA AND HEATING AIR IN THE MANUFACTURE OF PRODUCER GAS.

APPLICATION FILED AUG- 30. 1907.

- air passing through thegas producer.

U ITED srn'rns arana? iPFFiCE..-

WILLIAM JOHN CROSSLEYAND THOMAS RIGBY, or OP-E'NS'HAW, NEAR MANCHESTER,

. ENGLAND.

rnocnss on anoovname amaomm Am HEATING AIR PRODUCER-GAS.

IN THE MANUFACTURI Specification of Letters Ya'tent.

Patented April 28,1905.

To-all whom it may concern:

Be it known thatwe, WILLIAM JOHN Cnoss LEY and THOMAS RIGBY, both subjects of Great Britain, residing at ()penshaw, near Manchester, in the county of Lancaster, England, have invented new and useful Improvements in Processes-of Recovering Am.- monia and Heatin Air in the Manufacture pflroduc'er-Gas, 0 which the following is a specification.

This invention has for its object improvements' in the process of recovering ammonia and heating air in the manufacture of producer as. In such a process in order to obtain a ar 'e yield of ammonia it is desirable to. work the producers at a .low temperature and this is usually done by arranging for a large quantity of steam to be mixed with the Aportionof the excess of steam passes throughthe producer undecomposed and to make the process an econom c success it is not only necessary to recover the ammoniabut it .is essential that the great quantity of latent heat present in the water vapor should be re covered from the gas. In most of the processes employed the ammonia is recovered at a temperature above that at which the water vapor is condensed and before it is condensed, but in the British patent granted to the said Thomas Rigb 20716 of 1901 a process is described in the 5 ecifica tion which was calculated to simp ify methods hitherto in use by condensing the water vapor and tars in the gas before the ammonia was absorbed and this was done in a special way as described in th aforesaid structionand-was split up into compartments with the object of making zones 0 tempera- .ture the water contained in the washer trav. cling constantly in the direction of the hottest end. This hotwater was then pumped through an air saturating tower, with the- )b' and numbered.

ject of saturating the air supply to the pro-- ducers with-water vapor and cooling the water, the cool water flowing back to the coolest end of the washer and then m-ciztulated. I This ap aratus was also arranged in such a manner t at the ammonia was not lost being passed onwards with the gases to'ana'mmonia absorbing tower.

In the present invention we add sulfuric acid to the water circulating in the washer 111 such quantities that there is always p 1 in the liquor a small quantity of frees-acid and thus a fairlyconcentrated solution of sul fateof: ammonia is obtained and circulated instead of water. Y thus becomes the medium for inter-changing The actual sulfateliquor 7 the heat of the gas and the water vapor condensed' and also washes the gas, the small percentage of free acid present in the liquor absorbing the ammonia in-the gas in avery cfiicient manner.

, It will be understood, that thewater vapor gom the gas condensed by the liquor in the asher is added to this li uor'and is more or less afterwards recovere in the air satul'iating tower, portions of the liquor being taken off as required for further concentration by evaporation and crystallization in the usual manner;

In the accompanying sheet of drawinlgs Figure 1,is an elevation-of the genera rangement of apparatus constructed accord-- in to our invention and Fig. 2 is a plan view of ig. 1.

The ap aratus shown in the drawin that whic we prefer to use but we wish it to be understood that We do not limit our claims tothis particular form, or arrange -ment of apparatus, as it is obvious that the principles of the invention mayv be applied in a great many different ways.- Also we may use any other kind of ap aratusinstead of, or in addition to, the was er and the air saturating. tower previously referred to so long as the same body of liquor circulates through them, cooling the gas, washing it, icondensing its'water vapor and absor -its ammonia during one part of its circuit ing and heating and saturating the air supplied to the producer during the other part "of its circuit. a a

producers and air superheating appara s, enters the washer at a and,'passing into he Inoperation, the gas after leaving thegs finally leaving the washer atb.

furie acid and we fin successive compartment, it meets the spray raised by the paddles in each compartment The ten!- perature in each compartment varies the quor flowing along the bot-tom of the washer I v The l in the opposite direction to the heated liquor leaves the washer by means of the sealed pipe 03 and enters the hot well e suitably-arranged with baiiies g.

The pump it is arranged to pump the liquor up a. pipe f, from the hot well to the top or" an air saturating. tower k from whence itis distributed uniformly down checker work Z with which the tower is packed. Air from the blower m enters the air tower at n and is blown through the checker work in' the op osite direction to the down coming cirou ating'liquor and leaves the top of the air saturating tower 7c saturated with water Va or. The circulating sulfate liquor leaves the foot of" the air saturating tower considerabiy lower in temperature and" passes into the battle box 1) from whence it flows by gravity along the pipe s back to the cool end of the Washer to be again circulated ends on continuously.

We find in practice that any ammonia contained in the tar or other impurities brought down in the washer is absorbed by the sulfate"- liquor so that practically all the ammonia contained in the gas is recovered and corn Verted into sulfate of ammonia; a greater yield of ammonia per ton of fuel can thus be obtained. Any diiliculties which might have been expected owing to dust and tar in the liquor have been obviated by using small traces of sulliquor containing only that there is no dilliculty in separating dust and tarirom su h liquor.

When considerable quantities of dust are present in the gas or when they are at'such a nigh ten'iperatm'e that they would melt load it may be advantageous to treat the gas with water previous to its entrance to the con densing and absorbing apparatus and it is obvious that such details may be added if found desirablewithout sacrificing the principles of the invention.

As there is no need to keep in the sulfate liquor a greater proportion than the half of one per cent. of free sulfuric acid we are able to use cast iron freely in the construction of their iparatus in place of the usual lead lining, the wear and tcar ol materials with suchv dilute liquors being considerably reduced.

We declare that what we claim and desire to secure by Letters Patent ol' the lnitcd States is 1. The process of recovering ammonia and heating air in the nntnul'acture of ously sulfate liquor and. bringing producer gas in contact therewith so as to absorb thc ammonia, cool and wash the gas, condense the water vapor and simultaneously heat and saturate the air supplied to the producers with said sulfate liquor, substantially as and for the purposes herein described.

2. The process of recovering ammonia and heating air in the manufacture oi producer gas which consists essentially in combining in one operation and by the use ofsulfate liquor as the. regenerative or heat interchanging medium, the recovery of the latent heat from the gas and the heating and saturation with water vapor of the air on its way to the generator.

in testimony whereof we have signed our names to this specification in the presence of two subscribing wunesses.

WILLIAM JOHN RUSSLEY. THOMAS RIQBY.

'11 ncsses:

Josnrn .Jonns, h onnn'r H A am s! )N producer gas which consists in cuculatmg cont-lun 

